• Journal of Positioning, Navigation, and Timing
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• 제12권4호
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• pp.437-445
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• 2023

A space system refers to a network of sensors, ground systems, and space-craft operating in space. The security of space systems relies on information systems and networks that support the design, launch, and operation of space missions. Characteristics of space operations, including command and control (C2) between space-craft (including satellites) and ground communication, also depend on wireless frequency and communication channels. Attackers can potentially engage in malicious activities such as destruction, disruption, and degradation of systems, networks, communication channels, and space operations. These malicious cyber activities include sensor spoofing, system damage, denial of service attacks, jamming of unauthorized commands, and injection of malicious code. Such activities ultimately lead to a decrease in the lifespan and functionality of space systems, and may result in damage to space-craft and, lead to loss of control. The Cybersecurity Adversarial Tactics, Techniques, and Common Knowledge (ATT&CK) matrix, proposed by Massachusetts Institute of Technology Research and Engineering (MITRE), consists of the following stages: Reconnaissance, Resource Development, Initial Access, Execution, Persistence, Privilege Escalation, Defense Evasion, Credential Access, Discovery, Lateral Movement, Collection, Command & Control, Exfiltration, and Impact. This paper identifies cybersecurity activities in space systems and satellite navigation systems through the National Institute of Standards and Technology (NIST)'s standard documents, former U.S. President Trump's executive orders, and presents risk management activities. This paper also explores cybersecurity's tactics attack techniques within the context of space systems (space-craft) by referencing the Sparta ATT&CK Matrix. In this paper, security threats in space systems analyzed, focusing on the cybersecurity attack tactics, techniques, and countermeasures of space-craft presented by Space Attack Research and Tactic Analysis (SPARTA). Through this study, cybersecurity attack tactics, techniques, and countermeasures existing in space-craft are identified, and an understanding of the direction of application in the design and implementation of safe small satellites is provided.

• 한국산학기술학회논문지
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• 제19권2호
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• pp.429-435
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• 2018

인간의 거주환경에 있어서 공간은 매우 중요한 역할을 한다. 공간은 단순한 거주의 공간을 벗어나 삶의 직접적인 체험과 경험의 확장이 이루어지는 곳이다. 특히 생활공간의 중요성이 인식되는 부엌은 최근 텔레비전 프로그램을 통해서 일상성의 문화가 부각되고 있다. 그로인한 일상성의 공간을 대표하는 부엌은 매우 중요한 생산과 기능에 따른 소통의 역할을 강조하는 텔레비전 문화를 형성하고 있다. 부엌은 다양한 경험이 창발 하는 공간이다. 음식을 조리하고, 맛을 경험하고, 가족구성원간의 소통으로 이어지는 커뮤니케이션의 재매개 현상이 이루어지는 공간이다. 부엌의 수용적 공간의 특성은 음식을 통해서 공간의 소통을 이끌어내고 발전시키는 역할을 수행한다. 그러므로 본 연구에서는 tvN 의 <윤식당1>의 프로그램 텍스트 분석을 통해 부엌의 생산과 기능에 따른 소통의 관계를 분석하는데 목적을 갖고 있다. 본 연구의 분석 결과는 인간에게 있어서 부엌의 공간이 다양한 감각기관의 반응을 이끌어내고 문화적 할인의 격차를 최소화하는 과정에서 새로운 경험의 확대를 이끌어내는 것으로 나타났다. 또한 공간을 통해서 다양한 문화의 공존과 시간성이 내재되어 있는 안락함과 편안함을 제공하는 것으로 분석된다.

• 교육녹색환경연구
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• 제17권3호
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• pp.46-53
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• 2018

본 연구는 중학교 자유학기제 전면 시행에 따른 학습활동 공간, 학생자치 등 학생활동 공간, 학생들간의 소통 및 지역사회와의 공동체 형성을 위한 공간 등으로 학교 식생활관의 식당을 다목적공간으로 활용할 수 있는 방안을 위한 교육공동체의 인식을 분석하는데 목적을 두고 있다. 이에 본 연구에서는 학교 식당의 다목적 공간 활용에 관한 인식조사 하였으며 분석 결과 첫째, 식당 공간을 운영하는 중학교의 거의 대부분이 식사 이외의 다른 용도로 활용한 경험이 없는 것으로 나타났으며, 둘째, 다른 용도로 활용하지 않은 이유는 위생관리의 어려움이 가장 많은 것으로 분석되었다. 셋째, 학교 식당공간의 일부를 유리벽이나 가변형의 벽체로 구획하여 다른 용도로 사용하는 방안에 대하여 찬성하는 이유는 중학교 자유학기제 활용 등 교육과정 운영을 위한 학습 공간 지원과 학생들간의 소통 공간 확보를 위해서라고 분석되었다. 넷째, 식당공간의 다목적으로 활용 가능한 용도로는 영양 식생활 교육 공간이 가장 많았고, 다음으로 자유학기 등 교육과정 운영, 학생 간의 소통 공간 순으로 나타났다. 다섯째, 학교 식당공간을 다용도로 활용 시 공간 조성 방향에 대해서는 공간의 가구는 효율적인 공간 활용이 가능하도록 이동과 조합이 편리한 것을 설치하는 것이 중요한 것으로 나타났다.

• 한국정보기술응용학회:학술대회논문집
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• 한국정보기술응용학회 2005년도 6th 2005 International Conference on Computers, Communications and System
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• pp.65-68
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• 2005

In this paper, an algorithm to extract bar-space area is suggested. In a section of bar-code space area the threshold value is computed, and bar and space are extracted according to threshold value. PDF417 is used everyday life and printed in many different materials. The printed PDF417 is especially influenced by various light source. The decision of bar and space is very hard under the change of illumination. The fixed threshold value to distinguish the bar and space can not be applied. in these cases, The proposed algorithm is developed to investigate variable threshold. The variable threshold can be obtained by simple calculation.

• 한국실내디자인학회논문집
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• 제14권6호
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• pp.103-111
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• 2005

Since the Industrial Revolution in the 18th century, the production system adopted mechanization and mass production to popularize and standardize overall society. The architectural space removed basic desire of men on the decoration to neglect historical and regional continuity of the architecture and to make uniform designs, so that human sensibility and emotion were excluded. The architectural space had arbitrary and functionalism features in accordance with such a social change to display abstract space having no personality. The limitation expanded value of the space that was not lot possession and residence but for communication with men to express object factors. However, the object factors of the space were expressed in each factor consisting of either material factors or non-material factors. This study investigated interaction of the space by both expressive interaction and potential interaction to find out key words for making frames of the investigation and to examine cases comprehensively. The purpose of the study was to recover relations between the space and men in horizontal way and mutual communication and to present possibility integrating men and space.

• 한국화재소방학회논문지
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• 제31권5호
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• pp.117-122
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• 2017

밀폐된 공간에서 통신인프라가 파괴될 경우, 긴급 유 무선 통신환경을 구축하여 화재진압 및 소방관 위치확인을 통한 보다 안전한 재난대응환경 확보가 필요하다. 본 연구에서는 Ultra-Wide Band (UWB) 무선통신망을 이용하여 밀폐된 실내 통신환경을 구축하기 위해 6가지 실내환경에 대해 단일 UWB 통신모듈에 대한 통신측위 성능평가를 최대 20 m까지 측정하였다. UWB 통신주파수 각 대역별 6개 채널에 대한 실내환경 통신거리 측정 결과, 개방공간(평균 15.5 m, 최대 20 m), 복도(평균 17.33 m, 최대 20 m), 실내집기류 존치 실내(평균 15.3 m, 최대 20 m), 수직계단(평균 4.33 m, 최대 6 m), 방화문 폐쇄 수평공간(평균 6.5 m, 최대 17 m)으로 나타났다. 이중 7번 채널인 6489.6~1081.6 MHz 주파수 대역에서 통신성능과 거리성능이 가장 우수한 것으로 나타났다. 이에 UWB 통신모듈을 20m 간격으로 설치하고 멀티채널을 이용할 경우 밀폐공간에서 통신환경 구축이 가능한 것으로 판단된다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권9호
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• pp.3572-3593
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• 2015

This article investigates the topology control problem in the space information network (SIN) using a hierarchical autonomous system (AS) approach. We propose an AS network topology control (AS-TC) algorithm to minimize the time delay in the SIN. Compared with most existing approaches for SIN where either the purely centralized or the purely distributed control method is adopted, the proposed algorithm is a hybrid control method. In order to reduce the cost of control, the control message exchange is constrained among neighboring sub-AS networks. We prove that the proposed algorithm achieve logical k-connectivity on the condition that the original physical topology is k-connectivity. Simulation results validate the theoretic analysis and effectiveness of the AS-TC algorithm.

• Journal of the Optical Society of Korea
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• 제20권3호
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• pp.368-380
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• 2016

There is no doubt that adaptive optics (AO) is the most promising method to compensate wavefront disturbance in free space optics communication (FSO). In order to improve the performance of the AO system described by discrete-time linear system model with time-delay and implicit phase turbulent model, new controllers based on a Kalman filter and its extensions are proposed. Based on the standard Kalman filter, we propose a fading memory filter to deal with the ruleless strong interference; sequential and U-D filters are applied to reduce implementation complexity for the embedded controllers. Theoretical analysis and the numerical simulations show that the proposed fading memory filter can upgrade the performance for AO systems in consideration of the unforeseen strong pulse interference, and the sequential and U-D filters perform well compared with a Kalman filter.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(1)
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• pp.335-338
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• 2002

For high data rate transmission over wireless fading channels, space-time trellis ceding techniques can be employed to increase the Information capacity of the communication system dramatically. In this paper, we consider the concatenated space time LDPC (Low Density Parity Check) codes. Extra ceding gains In addition to the diversity advantage is shown to be achieved for certain space-time trellis codes transmitted over quasi-static lading channels.

• 디지털산업정보학회논문지
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• 제11권1호
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• pp.121-133
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• 2015

IoT utilized network vitalization between objects are being rapidly established within current IT communication environment. Therefore the worth of smart mirrors is rising for it is a tool to allow online network between objects to be possible in human communication environment. For effective IoT generation's communication, this research intends to evaluate the smart mirror's value for practical uses based on the users' experiences. For the UX evaluation according to the locations where it will be used, Peter Morville's Honeycomb model and Jocob Nielsen's usage evaluation principles were referred to analyze effectiveness of 4 factors, utilization convenience, communication effectiveness, mass interest and space adequateness on households, public places and work places. Hence, we have were led to an objective result through statistical analysis method based on survey. As a result, we have confirmed the smart mirror's positive influence on the users' effective communication in all places. Especially in households, utilization convenience and space adequateness appeared to be high that confirmed sufficient users' need for the home-automation services. In public places, the communication effectiveness and space adequateness ranked high to confirm that the smart mirror utilization is adequate to provide location information. Also, in work places, the mass adequateness was high that we were able to confirm that supply of work place-specific service contents would bring meaningful results to the users. The smart mirrors are the adequate method to provide effective communication in IoT generation with high possibilities in further development.